Commuters in the UK’s 25 most congested towns and cities waste an average of 127 hours a year stuck in traffic, according to a study.

Analysis of journey times for the TomTom Traffic Index found that drivers spent the equivalent of more than five extra days in their vehicles last year than they would have if there were no queues.

Congestion was 4% worse than 2014, with the problem increasing in 17 of the 25 towns and cities in the report.

Experts calculated that congestion across the UK has grown 14% over the past five years, while in the rest of Europe the problem has eased by 3%.

Belfast is the UK city with the most serious hold-ups - and the 14th worst in the world - with average journey times 40% slower than if traffic was flowing freely, according to the study.

This figure rises to 86% during the evening peak in the Northern Ireland capital, with drivers wasting an overall average of 195 hours behind the wheel - equivalent to more than eight days.

London is the 20th most congested city in the world - and the second worse in the UK - with average trips 38% slower, rising to 66% in the after-work rush.

Next on the list are Manchester and Edinburgh - with journeys taking 37% longer - followed by Brighton (34%), Hull (33%) and Bournemouth (32%).

Only Nottingham, Portsmouth, Middlesbrough and Preston have shown slight decreases in congestion out of the 25 UK towns and cities in the report.

The analysis of 14 trillion pieces of traffic data worldwide found that commuters in Mexico City face the worst congestion as they endure an average of 59% extra driving time, rising to 94% in the evening peak.

The next most congested large cities are Bangkok (57%), Istanbul (50%) and Rio de Janeiro (47%) - which is hosting the Olympic Games in August.

Ralf-Peter Schaefer of TomTom Traffic said: “Building new motorways and ring roads doesn’t eliminate congestion. More must be done to better manage existing road space and to spread demand.